• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.46
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• pp.93-101
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• 1998

A great number of firms have used overall equipments effectiveness index to evaluate the effect of TPM activities. Overall equipments effectiveness is very useful index to emphasize the need of decreasing equipments loss time when TPM system is first implemented. And it is powerful to evaluate prductivity growth rate according to TPM activities when GNP growth rate is high level. However, during the depression period, the increase of overall equipments effectiveness does not contribute fully to the cost down, the reason is that demand is falling. In this paper, we present the rectified TPM activities which can be applied to the depression period, and analysis the improvement activities of production part how to contribute to the cost down,

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.519-523
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• 1993

In this paper, the variable structure model following control scheme is proposed for the nonlinear robot manipulator system. The proposed control system guarantees that the system state is in the sliding mode for all time. Therefore, error transient can be prescribed in advance for all time. Furthermore, overall system is globally exponentially stable. Chattering problem is reduced by the introduction of a boundary layer. Simulation results are given to show the usefulness of the proposed control scheme.

• Korean Management Science Review
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• v.13 no.1
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• pp.13-27
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• 1996

This paper considers the sequencing problem in mixed model assembly lines with hybrid workstation types and sequence-dependent setup times. Computation time is often a critical factor in choosing a method of determining the sequence. We develop a mathematical formulation of the problem to minimize the overall length of a line, and present a tabu search technique which can provide a near optimal solution in real time. The proposed technique is compared with a genetic algorithm and a branch-and-bound method. Experimental results are reported to demonstrate the efficiency of the technique.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.341-341
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• 2000

This paper presents a sliding mode control(SMC) design method for single input linear systems with uncertainties and time delay in the state. We define a sliding surface for the augmented system with a virtual state which is defined from the nominal system. We make a virtual state from optimal control input using LOR(Linear Quadratic Regulator) and the states of the nominal system. We construct a controller that combines SMC with optimal controller. The proposed sliding mode controller stabilizes on the overall closed-loop system.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.12
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• pp.1610-1617
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• 1988

In this paper, a robust discrete-time adaptive control with compensation is proposed for single-input single-output discrete-time plants which have unmodeled dynamics. The stability of the overall system is studied using the conic sector stability theorems when a normalized constant gain parameter adaptation algorithm and a properly chosen compensation are used. An illustrative exmple shows that this compensation can also increase the parameter adaptation speed. And a method of compensation using the adaptive observation is also discussed.

• The Journal of the Acoustical Society of Korea
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• v.3 no.1
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• pp.25-35
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• 1984

This paper analysis the Dynamic Time Warping algorithms for time normalization of speech pattern and discusses the Dynamic Programming algorithm for spoken Korean isolated digits recognition. In the DP matching, feature vectors of the reference and test pattern are consisted of first three formant frequencies extracted by power spectrum density estimation algorithm of the ARMA model. The major differences in the various DTW algorithms include the global path constrains, the local continuity constraints on the path, and the distance weighting/normalization used to give the overall minimum distance. The performance criterias to evaluate these DP algorithms are memory requirement, speed of implementation, and recognition accuracy.

• Proceedings of the Safety Management and Science Conference
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• 2008.11a
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• pp.35-39
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• 2008

This paper considers the sequencing of products in mixed model assembly lines. The sequence which minimizes overall utility work in car assembly lines reduce the cycle time, the number of utility workers, and the risk of conveyor stopping. The sequencing problem is solved using Tabu Search. Tabu Search is a heuristic method which can provide a near optimal solution in real time. Various examples are presented and experimental results are reported to demonstrate the efficiency of the technique.

• Culinary science and hospitality research
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• v.21 no.5
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• pp.38-49
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• 2015

The purpose of this study was to investigate tangible clues influence on perceived risk and overall satisfaction of customers at family restaurant in South Korea. In this research overall CFA and SEM were employed to analyze the data. Tangible clues were divided to 3 factors and perceived risk to 6 factors. Tangible clue 1 'physical evidence', had negative(-) influence on financial risk(p<0.01), performance risk(p<0.01) and psychological risk(p<0.001). Tangible clue 2 'employee' affected negatively(-) time risk(p<0.001), performance risk(p<0.001), psychological risk(p<0.01) and social risk(p<0.001). And tangible clue 3 'service process' influenced negatively(-) physical risk(p<0.01), time risk(p<0.05), financial risk (p<0.001) and performance risk(p<0.01). And among customer's perceived risks, 3 factors(time risk~p<0.001, performance risk~p<0.001, social risk~p<0.001) influenced negatively(-) their overall satisfaction. Through these results, it appears that customers perceive various tangible clues and risks at family restaurants. And they are likely to satisfy or dissatisfy according to their perceived risks. As a result, food service companies need to research various customers' perceived risks as important marketing strategy, and reduce them for increase and induction of customers' satisfaction.

• Quality Improvement in Health Care
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• v.8 no.1
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• pp.74-83
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• 2001

Background : Since a Gamma Knife had been installed on December 1997, 405 patients have been treated until December 1999 at department of neurosurgery of Seoul National University hospital. The authors analyzed results of a work to improve satisfaction of Gamma Knife surgery patients and to reduce hospital length of stay. Methods : To understand main discontent of patients, a pre-survey was performed from October 1998 to December 1999 using a questionnaire. By Analyzing 93 questionnaire received from 234 patients, pain on frame application, explanation before surgery, waiting time before surgery, waiting time before medical procedure were main discontent factor and overall satisfaction ratio was 71.0%. To improve satisfaction ratio, several quality improvement activity works were designed and applied to 123 patients during the period between January 2000 and September 2000. The same questionnaire were analyzed. Works to reduce the patient hospital LOS were devised and applied during the same period. Results : The overall satisfaction ratio of Gamma Knife radiosurgery patients was increased to 83.7%(P=0.10). The main factor to improve satisfaction ratio was to reduce waiting time(P=0.05) and improvement of discomfort during the surgery(P=0.06). The average LOS was reduced from 3.1 to 2.7 days(P=0.003). Conclusion : As a result of quality assurance activities, the overall satisfaction ratio of patients was improved and LOS was reduced. The pain during frame application was remained as a main discontent factor and a further study is required to reduce this pain.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6563-6568
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• 2013

Background: Tobacco use and quit attempts are two key indicators of the Global Adult Tobacco Survey (GATS) that assess quit attempts among current as well as former tobacco users. The relevant data have inherent policy implications for tobacco cessation programme evaluation. This study aimed to review the concepts of quit attempt assessment and quantifying invalid responses considering GATS-India data. Materials and Methods: GATS assessment of tobacco use and quit attempts were examined in the current literature. Two categories of invalid responses were identified by stratified analysis of the duration of last quit attempt among current users and duration of abstinence among former users. Category A included absolute invalid responses when time-frame of assessment of current tobacco use and less than former tobacco use were violated. Category B included responses that violated the unit of measurement of time. Results: Current daily use, current less than daily use and former use in GATS were imprecisely defined with overlapping of time-frame of assessment. Overall responses of 3,102 current smokers, 4,036 current smokeless users, 1,904 former smokers and 1,343 former smokeless users were analyzed to quantify invalid responses. Analysis indicated overall 21.2% (category A: 7.32%; category B: 17.7%) and 22.7% (category A: 8.05%; category B: 18.1%) invalid responses among current smokers and smokeless users respectively regarding their duration of last quit attempt. Similarly overall 6.62% (category A: 4.7%; category B: 2.3%) and 10.6% (category A: 8.6%; category B: 3.5%) invalid responses were identified among former smokers and smokeless users respectively regarding their duration of abstinence. Conclusions: High invalid responses for a single assessment are due to the imprecise definition of current use, former use and quit attempt; and failure to utilize opportunity of direct data entry interface use during the survey to validate responses instantly. Redefining tobacco use and quit attempts considering an appropriate timeframe would reduce invalid responses.